The gain of an optical amplifier is typically not flat over the response of the amplifier--which means that different levels of gain are applied to optical signals of different wavelengths. FIG. 1 illustrates the response of a typical erbium doped optical amplifier. Referring to the section designated R, a greater level of amplification occurs for those signals having wavelengths from 1553 nm to 1559 nm than for those signals in the R region and having wavelengths from 1548 nm to 1552 nm. Thus, some optical signals are amplified greater than other optical signals passing through the optical amplifier. This difference in amplification is referred to herein as power divergence, and needs to be dealt with.